1.2 Big Idea 1: Evolution

1.2 Big Idea 1: Evolution

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1.  Evolution is the unifying topic in biology

   1. a unifying concept - evolution explains so many aspects of biology

   2.  supported by independent evidence from:

      1.  paleontology

      2.  geology

      3. genetics

      4. molecular biology and genomics

      5.  developmental biology

      6. biogeography

      7. behavioral ecology

2. changes in organisms to better adapt to their environment over long periods of time

3.  natural selection is the process that makes modification (adaptations to environmental change)

   1. process that selects which traits are best fit for survival

   2. those best fit traits are passed onto the next generation

   3. selective agents comes from the environment

      1.  biotic such as other living things

      2. abiotic such as climate

4. mutations fuels selection

   1. introduces new variations among members of a population

5. organisms with the advantageous traits will have more offspring

   1. survivors have the genetic code for the adaptation

   2. over a long period of time the changes can accumulate and the population will be drastically reshaped

6. Taxonomy organizes diversity

   1. the discipline of identifying and grouping organisms according to certain rules. 

   2. an evolutionary tree is like a family tree

      1. the descendants on the tree are connected to a common ancestor

      2. explains how living organisms arose from a single ancestor

   3. makes sense of the biodiversity (or variety of life) on Earth

7. Systematics is the study of evolutionary relationships between organisms

8. Several of the basic classification categories (or taxa)move from most to least inclusive:

   1. species (most exclusive, least inclusive group)

   2. genus

   3. family

   4. order 

   5. class 

   6. phylum

   7. kingdom

   8. domain (least exclusive, most inclusive group)

      1. each successive group includes more groups. 

      2. species placed within one genus share many similarities

      3. species placed within a kingdom only share general characteristics

9. Domains are the most inclusive groups

   1. There are three different domains:

      1. domain Bacteria

      2. domain Archaea

      3. domain Eukarya

   2. Domains Bacteria and Archaea are prokaryotic where cells do not contain membrane bound organelles such as the nucleus

      1. Each contains a single kingdom Eubacteria (domain bacteria) and Archaebacteria (domain archaea)

      2. single-celled organisms might be structurally simple but metabolically complex

         1. Archaea can live in exotic environments that would kill most other organisms

            1. very salty (salt lakes)

            2. very hot (volcanic vents)

            3. low pH or very acidic (hot springs)

         2. Bacteria have adapted to live in almost all other environments

            1. water

            2. soil

            3. atmosphere

            4. and within us!

   3. Domain Eukarya are eukaryotic (hence the name) where cells do contain membrane organelles 

      1. Contains four kingdoms

         1. Protista

            1. complex single celled organisms (can exist in filaments or colonies or work together as a multicellular organism

            2. absorb nutrients, photosynthesize, or ingest food

            3. examples include algae, protozoans, slime molds, and water molds

         2. Fungi

            1. mostly multicellular (making up filaments) with complex cells and tissues while some are single celled (like yeast)

            2. absorb food

            3. examples include mold, mushrooms, yeasts and ringworms

         3. Plantae

            1. multicellular, usually with specialized tissues containing complex cells

            2.  photosynthesize food

            3. algae, mosses, ferns, conifers, and flowering plants

         4. Animalia

            1. multicellular with specialized tissues containing complex cells

            2. ingest food

            3. examples include sponges, worms, insects, fishes, amphibians, reptiles, birds and mammals

10. A scientific name follows binomial nomenclature

    1. a two-part name written in Latin as a universally accepted method in science

    2. first part is the genus and the second part is the species written in italics with the first part of the name capitalized

       1. examples

          1.  mistletoe Phoradendron tomentosum

          2. human Homo sapiens

          3. corn Zea mays

    3. common names can tend to overlap with other known species and differ depending on location and language